I have problem in my post api when using join table in JPA - spring

Question

I am trying to create a Post API which will add a user to my database.
I have 3 tables:
1: ol__user
2: ol__roles
3: ol__users_roles
There is no relation between ol__user and ol__roles but ol__users_roles contains both table's Ids.
Data Model
I used #jointable annotation and my codes are written below :
#Entity
#Table(name = "ol__user")
#DynamicUpdate
#EntityListeners(AuditingEntityListener.class)
public class ol__user {
#Id
#GeneratedValue(strategy = GenerationType.AUTO,generator = "system-uuid")
#GenericGenerator(name="system-uuid", strategy = "uuid")
#Column(name = "id", unique = true, nullable = false)
private String user_Id;
#Column(name = "username", nullable = true)
private String username;
#Column(name = "password", nullable = false)
private String password;
#Column(name = "salt", nullable = true)
private String salt;
#Column(name = "is_active", nullable = false)
private Boolean is_active;
#Column(name = "create_at", nullable = true)
private Timestamp create_at;
#Column(name = "email", nullable = false)
private String email;
#Column(name = "password_requested_at", nullable = true)
private Timestamp password_requested_at;
#Column(name = "confirmation_token", nullable = true)
private String confirmation_token;
#Column(name = "deleted_at", nullable = true)
private Timestamp deleted_at;
#Column(name = "last_login_at", nullable = true)
private Timestamp last_login_at;
#Column(name = "dtype", nullable = false)
private String dtype;
#Column(name = "temporary_password_set_at", nullable = true)
private Timestamp temporary_password_set_at;
#Column(name = "action_token", nullable = true)
private String action_token;
#Column(name = "referral_customer_email", nullable = true)
private String referral_customer_email;
#Column(name = "newsletter_used_flag", nullable = true)
private Boolean newsletter_used_flag;
#Column(name = "phone", nullable = true)
private String phone;
#Column(name = "status_type", nullable = true)
private String status_type;
#Column(name = "status_state", nullable = true)
private String status_state;
#Column(name = "first_name", nullable = true)
private String first_name;
#Column(name = "last_name", nullable = true)
private String last_name;
#Column(name = "external", nullable = true)
private Boolean external;
#Column(name = "api_key", nullable = true)
private String api_key;
#Column(name = "allow_point_transfer", nullable = true)
private Boolean allow_point_transfer;
#OneToOne(cascade = CascadeType.ALL )
#JoinTable(name="ol__users_roles",
joinColumns =
{#JoinColumn(name="user_id",referencedColumnName = "id")},
inverseJoinColumns =
{#JoinColumn(name="role_id",referencedColumnName = "id")}
)
private ol__roles roles;
public ol__roles getRoles() {
return roles;
}
public void setRoles(ol__roles roles) {
this.roles = roles;
}
setter AND getters..
here is my second table code:
#Entity
#Table(name="ol__roles")
#EntityListeners(AuditingEntityListener.class)
public class ol__roles {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id", unique = true, nullable = false)
private Integer roleId;
#Column(name="name",nullable = true)
private String name;
#Column(name="role",nullable = true)
private String role;
#Column(name="is_master",nullable = true)
private Boolean is_master;
setter and getters ...
here is my third table code:
#Entity
#Table(name="ol__users_roles")
#EntityListeners(AuditingEntityListener.class)
public class ol__users_roles {
#Id
#Column(name = "user_id",unique = true,nullable = false)
private String user_id;
#Column(name = "role_id",unique = true,nullable = false)
private Integer role_id;
setter and getters ...
ol__users_roles doesn't have a unique id and just has this 2 foreign keys.
In my Controller, I have this code:
#PostMapping("/admin/data")
public ol__user createUserAdmin(#Valid #RequestBody ol__user ol__user)
{
return userRepository.save(ol__user);
}
whenever I call this API :
{
"username": "adminssroos",
"firstName": "adminsss",
"lastName": "adminssnew",
"email": "nejatianadmhhhs#admin.com",
"phone": "09354006090",
"salt": "123455",
"roles": {
"role_id": "13"
},
"password": "123#123#Mm",
"is_active": true,
"create_at": "2020-03-01",
"dtype": "admin"
}
I got the error below:
> 2020-04-07 02:27:48.628 INFO 13242 --- [nio-8080-exec-1]
> o.s.web.servlet.DispatcherServlet : Completed initialization in
> 10 ms Hibernate:
> select
> nextval ('hibernate_sequence') Hibernate:
> insert
> into
> ol__roles
> (is_master, name, role, id)
> values
> (?, ?, ?, ?) 2020-04-07 02:27:49.157 WARN 13242 --- [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL
> Error: 0, SQLState: 23502 2020-04-07 02:27:49.157 ERROR 13242 ---
> [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : ERROR:
> null value in column "role" violates not-null constraint Detail:
> Failing row contains (18, null, null, null). 2020-04-07 02:27:49.175
> ERROR 13242 --- [nio-8080-exec-1] o.h.i.ExceptionMapperStandardImpl
> : HHH000346: Error during managed flush
> [org.hibernate.exception.ConstraintViolationException: could not
> execute statement] 2020-04-07 02:27:49.242 ERROR 13242 ---
> [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] :
> Servlet.service() for servlet [dispatcherServlet] in context with path
> [] threw exception [Request processing failed; nested exception is
> org.springframework.dao.DataIntegrityViolationException: could not
> execute statement; SQL [n/a]; constraint [role]; nested exception is
> org.hibernate.exception.ConstraintViolationException: could not
> execute statement] with root cause
>
> org.postgresql.util.PSQLException: ERROR: null value in column "role"
> violates not-null constraint Detail: Failing row contains (18, null,
> null, null). at
> org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2440)
> ~[postgresql-42.2.5.jar:42.2.5] at
> org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:2183)
> ~[postgresql-42.2.5.jar:42.2.5] at
> org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:308)
> ~[postgresql-42.2.5.jar:42.2.5] at
> org.postgresql.jdbc.PgStatement.executeInternal(PgStatement.java:441)
> ~[postgresql-42.2.5.jar:42.2.5] at
> org.postgresql.jdbc.PgStatement.execute(PgStatement.java:365)
> ~[postgresql-42.2.5.jar:42.2.5] at
> org.postgresql.jdbc.PgPreparedStatement.executeWithFlags(PgPreparedStatement.java:143)
> ~[postgresql-42.2.5.jar:42.2.5] at
> org.postgresql.jdbc.PgPreparedStatement.executeUpdate(PgPreparedStatement.java:120)
> ~[postgresql-42.2.5.jar:42.2.5] at
> com.zaxxer.hikari.pool.ProxyPreparedStatement.executeUpdate(ProxyPreparedStatement.java:61)
> ~[HikariCP-3.2.0.jar:na] at
> com.zaxxer.hikari.pool.HikariProxyPreparedStatement.executeUpdate(HikariProxyPreparedStatement.java)
> ~[HikariCP-3.2.0.jar:na] at
> org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:175)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3176)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:3690)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.action.internal.EntityInsertAction.execute(EntityInsertAction.java:90)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:604)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.engine.spi.ActionQueue.executeActions(ActionQueue.java:478)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.event.internal.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:356)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:39)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.internal.SessionImpl.doFlush(SessionImpl.java:1454)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:511)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.internal.SessionImpl.flushBeforeTransactionCompletion(SessionImpl.java:3290)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.internal.SessionImpl.beforeTransactionCompletion(SessionImpl.java:2486)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl.beforeTransactionCompletion(JdbcCoordinatorImpl.java:473)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.beforeCompletionCallback(JdbcResourceLocalTransactionCoordinatorImpl.java:178)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl.access$300(JdbcResourceLocalTransactionCoordinatorImpl.java:39)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.commit(JdbcResourceLocalTransactionCoordinatorImpl.java:271)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.hibernate.engine.transaction.internal.TransactionImpl.commit(TransactionImpl.java:104)
> ~[hibernate-core-5.3.10.Final.jar:5.3.10.Final] at
> org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:532)
> ~[spring-orm-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:746)
> ~[spring-tx-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:714)
> ~[spring-tx-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:534)
> ~[spring-tx-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:305)
> ~[spring-tx-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
> ~[spring-tx-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
> ~[spring-tx-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:138)
> ~[spring-data-jpa-2.1.9.RELEASE.jar:2.1.9.RELEASE] at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
> ~[spring-data-commons-2.1.9.RELEASE.jar:2.1.9.RELEASE] at
> org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
> ~[spring-aop-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> com.sun.proxy.$Proxy115.save(Unknown Source) ~[na:na] at
> com.Loyalty.OpenLoyalty.Controllers.Ol__userController.createUserAdmin(Ol__userController.java:41)
> ~[classes/:na] at
> java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native
> Method) ~[na:na] at
> java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
> ~[na:na] at
> java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> ~[na:na] at
> java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na]
> at
> org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:892)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1039)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:908)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:882)
> ~[spring-webmvc-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
> ~[tomcat-embed-websocket-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:92)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:109)
> ~[spring-web-5.1.8.RELEASE.jar:5.1.8.RELEASE] at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:853)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1587)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
> ~[na:na] at
> java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
> ~[na:na] at
> org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
> ~[tomcat-embed-core-9.0.21.jar:9.0.21] at
> java.base/java.lang.Thread.run(Thread.java:830) ~[na:na]
I don't know why my API is inserting to ol__roles instead of ol__users_roles, anybody can help me?

Answer 1

I solved your problem. check this out:
ol__roles model:
#Entity
#Table(name="ol__roles")
#EntityListeners(AuditingEntityListener.class)
public class ol__roles {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
#Column(name = "id", unique = true, nullable = false)
private Integer id;
#Column(name="name",nullable = true)
private String name;
#Column(name="role",nullable = true)
private String role;
#Column(name="is_master",nullable = true)
private Boolean is_master;
#JsonIgnore
#ManyToMany(mappedBy="roles",cascade = {CascadeType.MERGE},fetch= FetchType.EAGER)
private Set<ol__user> users = new HashSet<ol__user>();
//getter and setters
}
ol__user model:
#Entity
#Table(name = "ol__user")
#DynamicUpdate
#EntityListeners(AuditingEntityListener.class)
public class ol__user {
#Id
#GeneratedValue(strategy = GenerationType.AUTO, generator = "system-uuid")
#GenericGenerator(name = "system-uuid", strategy = "uuid")
#Column(name = "id", unique = true, nullable = false)
private String id;
#Column(name = "username", nullable = true)
private String username;
#Column(name = "password", nullable = false)
private String password;
#Column(name = "salt", nullable = true)
private String salt;
#Column(name = "is_active", nullable = false)
private Boolean is_active;
#Column(name = "create_at", nullable = true)
private Timestamp create_at;
#Column(name = "email", nullable = false)
private String email;
#Column(name = "password_requested_at", nullable = true)
private Timestamp password_requested_at;
#Column(name = "confirmation_token", nullable = true)
private String confirmation_token;
#Column(name = "deleted_at", nullable = true)
private Timestamp deleted_at;
#Column(name = "last_login_at", nullable = true)
private Timestamp last_login_at;
#Column(name = "dtype", nullable = false)
private String dtype;
#Column(name = "temporary_password_set_at", nullable = true)
private Timestamp temporary_password_set_at;
#Column(name = "action_token", nullable = true)
private String action_token;
#Column(name = "referral_customer_email", nullable = true)
private String referral_customer_email;
#Column(name = "newsletter_used_flag", nullable = true)
private Boolean newsletter_used_flag;
#Column(name = "phone", nullable = true)
private String phone;
#Column(name = "status_type", nullable = true)
private String status_type;
#Column(name = "status_state", nullable = true)
private String status_state;
#Column(name = "first_name", nullable = true)
private String first_name;
#Column(name = "last_name", nullable = true)
private String last_name;
#Column(name = "external", nullable = true)
private Boolean external;
#Column(name = "api_key", nullable = true)
private String api_key;
#Column(name = "allow_point_transfer", nullable = true)
private Boolean allow_point_transfer;
#ManyToMany(cascade = {CascadeType.MERGE})
#JoinTable(name="ol__users_roles",
joinColumns={#JoinColumn(name="user_id")},
inverseJoinColumns={#JoinColumn(name="role_id")})
private Set<ol__roles> roles = new HashSet<ol__roles>();
//getters and setters
}
and that's it! you don't need to define any model for ol__users_roles.
hope this helps you!

Answer 2

you should not define a new table for role_user . this table created when you define #ManyToMany relationship between two table.
If any user has one role (#OneToOne) or some role (#OneToMany), you don't need role_user table .
If a user has some role so in role table created a column as foreign_key.
for excample :
public class user {
private String name ;
//another fields...
#OneToMany(mappedBy = "user", fetch = FetchType.LAZY , cascade = CascadeType.REMOVE)
private Set<Role> roles = new HashSet<>();
//getter & setter
}
public class Role{
private String role;
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "role_id")
#JsonIgnore
private User user ;
//getter & setter
}
NOTE : using #JoinTable create new table with to foreign_key.